DESCRIPTION
The SC1406G PowerStep controller is a High Speed, High Performance Hysteretic Mode PWM controller. Teamed with the SC1405 Smart Driver, it powers advanced Pentium® II and Pentium® III processors. It also directly supports Intels SpeedStep processors for even longer battery life. A 5-bit DAC, accurate to 0.85%, sets the output voltage reference, and implements the 0.925V to 2.00V range of the mobile Pentium® specifications. The hysteretic converter uses a comparator without an error amplifier, and therefore provides the fastest possible transient response, while avoiding the stability issues inherent to classical PWM controllers. Two linear regulator controllers, coupled with appropriate external transistors, produce tightly regulated 1.5V and 2.5V to complete the processor power solution. The SC1406G also features separate soft-start controls for the converter and the regulators, a TTLcompatible power good indication, logic enable, and low battery undervoltage lockout. Programmable current limiting uses a separate comparator to protect against overloads and short-circuits.
Semtech Corporation
